ORELLANA PROVINCE, Ecuador — Looking high into the treetops, Sebastian Ramirez searched for familiar faces. For the past year, he’s been following a group of spider monkeys. Each day, he and his team track one of them and take notes.

“We do what they do,” Ramirez said. “When they rest, we rest. When they move, we move.”

Apart from recording the monkeys’ behavior and noting their movements via GPS, the biologists have one main task as they continue their decade-long study.

“We never interfere with the animals,” he said. “Particularly because we’re in such a pristine environment.”

A female spider monkey named Eva led a small troupe through the forest canopy looking for fruit. Seeds rained down on the biologists as the monkeys stopped to eat.

After a few hours crashing through the rain forest, the biologists stopped and sat on a rough-hewn bench. About 30 meters in front of them, there was a small cave hidden from view. One by one, Eva and the other monkeys cautiously came down from the trees.

After checking and rechecking for predators, they disappeared into the cave to scoop up mineral-rich mud to eat.

After a decade observing each other, the monkeys trust the scientists. It’s a rapport that pays off, as the monkeys played and fought over the balls of mud, rewarding Ramirez and his team with rare insights into their behavior.

“This could only happen in an untouched environment like we have here,” he said. “We couldn’t have a study like this anywhere else.”

Yasuni National Park is unique. It’s regarded as one of the world’s most biodiverse places. A refuge to more than 20 types of endangered mammals, just 2½ acres of its Amazonian forest contains more than 100,000 species of insects, and is home to nearly as many kinds of trees and shrubs as there are in the United States and Canada, combined.

But this incredible natural richness is at risk.

In 2007, Ecuador’s government announced it wouldn’t drill for oil in an untouched section of Yasuni, what’s known as the ITT block. In exchange for leaving the oil in the ground, President Rafael Correa demanded $3.6 billion from developed countries. But Ecuador received just $13 million. Last year, Correa announced oil extraction would go ahead.

Since then, oil companies have been busy surveying Yasuni’s ITT block, with plans to start drilling in 2016. Correa says the project will help alleviate poverty, but members of the Waorani tribe, which has lived in the Amazon for centuries, say the drilling will disrupt their way of life. Scientists, meanwhile, say they’re concerned about the park’s fragile ecosystem.

A devastating spill

Wani and Humberto know all about oil. Once these Waorani tribesmen lived off the surrounding forest and river alone. But little by little, they’ve seen their traditional way of life whittled away. Now, they carve blowguns and spears to sell to tourists. They blame the changes on the arrival of oil exploration two decades ago.

“The oil companies talk about helping us,” Wani said. “But it’s a lie.”

Wani said his children and grandchildren get sicker more often now because of environmental pollutants and introduced diseases. But it’s the gravel road and oil pipelines at the entrance to their community, and the constant hum of a generator, which signal the greatest threats to their culture.

“Every day there are more cars and fewer animals,” he said. “[The oil companies] damage and pollute the land.”

The Waorani aren’t the only ones worried about the new drilling. A few hours upriver lies the impoverished town of Coca, the hub of Ecuador’s oil industry. For more than four decades, people here have lived side by side with oil. And while the industry drives the local economy, it’s taken a toll.

Last year, a broken pipeline spilled nearly 400,000 gallons of oil into the Coca River. The spill left Coca’s 65,000 residents without drinking water. The oil then floated downriver, through the western Amazon, all the way to Peru. A year later, the water in the Coca River still isn’t safe to drink.

Local journalist Jose Mateus said the spill was another reminder that the government needs to think beyond oil, and boost farming and other local industries as an alternative.

“Without doubt, oil is our only source of wealth, that’s why the president depends on it,” said Mateus. “But what happens when we run out of oil?”

The oil industry and its related jobs continue to lure people from all over Ecuador to the town of Coca, but many residents complain that decades of oil production have failed to improve their lives.

“I’ve lived here for 30 years and every time the scale of oil exploitation gets bigger,” said Washington Wilkes, a Coca resident. “But there’s little change in the communities.”

Another resident, Kira Espana, said that despite the oil boom, unemployment here is high.

“We’re single mothers with families, but we can’t find work,” she said. “There are no factories here offering jobs.”

Ecuador’s state oil company declined to speak to Al Jazeera America. But politicians from the ruling party insist that oil exploitation is Ecuador’s only option – and that the local communities will feel the benefit this time around.

“It’s a great challenge for our government to show the world that a small oil-producing country can extract oil, despite big environmental risks,” said Coca Mayor Anita Rivas, representing President Correa’s Pais Alliance Party. “But exploiting oil will allow future generations to leave poverty behind.”

A different way to develop?

The oil in the ITT has an estimated value of around $7 billion, and Ecuador hopes to extract up to a quarter of a million barrels per day by 2019. But some scientists argue that what’s above the ground could be worth far more.

A third of pharmaceutical drugs come from nature, and in Yasuni just a fraction of the trees and plants have been identified, let alone tested for medicinal value. Taking a break from examining young leaves, Phyllis Coley and her husband, Tom Kursar, said plants could hold the key.

The two American biologists have been working to save rain forests for the past 20 years, and they believe bio-prospecting, unlike oil, could offer long-term jobs.

“One of the things that we look at when we walk in the forest is the potential of this amazing diversity to be a pharmacy for lots of future human health needs,” Coley said. “And nowhere in the world has this pharmacy got more potential than here in the Yasuni area of Ecuador.”

One of the team’s Ecuadorian students is now determined to secure funding for bio-prospecting in Yasuni, targeting diseases specifically affecting her countrymen. It’s a long road, but one that could pay off in many ways.

Wani and Humberto looked out over what was jungle just a few decades ago. With new development coming, and the drone of generators in the distance, these Waorani elders worry that more oil will mean more roads and more people. They fear that one day there will be no animals left in the forest.

They said that the only way to ensure the survival of their way of life is through political means.

“We were born here … Our grandparents were born here,” Wani said. “We want the government to make this territory legally ours, so we can walk freely like we did when we were children.”